param_import: add mark_saved argument

Behavior of the 'param import' command:
- if no file provided, parameters are marked as saved (differs from before)
- if a file is provided: parameters are not marked as saved

src/lib/parameters/flashparams/flashparams.cpp

@@ -362,5 +362,5 @@ int flash_param_load()
 
 int flash_param_import()
 {
-	return param_import_internal(false);
+	return param_import_internal(true);
 }